title: Microbial ecology of autothermal thermophilic aerobic digester (ATAD) systems for treating waste activated sludge.
abstract: Despite their widespread use, our understanding of the microbial ecology of the autothermal thermophilic aerobic digesters (ATAD) used to dispose of sludge from wastewater treatment plants is poor. Applying both culture-dependent and molecular methods to two ATAD systems in Victoria, Australia treating different wastewaters revealed that their communities were highly specialized. Denaturing gradient gel electrophoresis (DGGE) profiling suggested differences in their population compositions and both changed over time. However, both showed low level biodiversity, and contained several novel bacterial populations. 16S rRNA clone library data and FISH analyses showed that Thermus thermophilus dominated both communities and that of a third ATAD plant in NSW (more than 90% of the total bacterial biovolume in repeated samples taken from each of the three ATAD plants). Culture-dependent methods also showed Geobacillus spp. were present in both Victorian communities. Nevertheless, the ecophysiology of these populations and their putative roles in sludge digestion remain unclear. FISH/microautoradiographic studies did not provide conclusive data elucidating which substrate/s T. thermophilus might utilize in the ATAD reactors.
authors.affiliation: Biotechnology Research Centre, La Trobe University, Bendigo, VIC 3552, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Hayes
authors.forename: Leonard
authors.initials: L
authors.lastname: Izzard
authors.forename: Robert
authors.initials: R
authors.lastname: Seviour
mesh_terms: D039903:Actinobacteria / Q000235:genetics; D001673:Biodegradation, Environmental; D058448:Biota; D003013:Clostridium / Q000235:genetics; D058645:Denaturing Gradient Gel Electrophoresis; D056506:Geobacillus / Q000235:genetics / Q000302:isolation & purification; D006358:Hot Temperature; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D059013:Microbial Consortia / Q000235:genetics*; D010802:Phylogeny; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012722:Sewage / Q000382:microbiology*; D016963:Thermus thermophilus / Q000235:genetics / Q000302:isolation & purification
chemical_list: D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012722:Sewage